Wood filler



Patented Dec. l2, 1922.

units save o'rn o v. STEWART, or WILKINSBURG, AND aueus'rn. rrnrzrnnn, or'ruiarnn PENNSYLVANIA, ASSIGNOBS r0 wns'rINcTHoUsn ELECTRIC & ivranus tcrunrno COMPANY, A CORPORATION or PENNSYLVANIA.

WOOD FILLER.

No Drawing.

and indentations in wood patterns used in.

casting, it being among the objects of this invention to produce a composition for fillin dents and small holes in such patterns, which is cheap, provides a moisture-resistant and strongly adherent mass, and one which hardens very readily.

lVood patterns, such as are used in making molds for casting metal, should have smooth surfaces in order that they may readily be removed from the sand without scarring or mutilating the surface thereof and in order that a smooth casting of the true shape may be formed.

In removing a pattern from the sand, after forming the mold, the molder often taps the same lightly with a hammer in order to more readily release it, thus making indentations in the surface.

Very often, also, nails are driven into a pattern when in the mold, in order that the molder may grasp the same to remove it, especially when the pattern is of large size or is in an awkward position.

Patterns also become damaged accidentally through dropping on a hard floor or being hit by metallic objects of various sorts, and it has been customary hitherto to remove sections of a pattern which became seriously injured and replace the same by new wood. Such an operation is expensive and requires considerable time.

It has also been proposed to fill indentations of small size with putty, paint, iron filler, wood filler, and various other mixtures, but such compositions did not generally become hard, did not adhere perinanently to the wood, or left the surface rough.

Our invention obviates these disadvan- Application filed December 16, 1920. Serial No. 431,288.

tages and not only results in a coating or filling material which is hard and adherent, but one which may be prepared very readily at small cost.

In practising our invention, we take a viscous. solution of shellac or similar materialand add to the same a filling material, such as whiting, and form the mixture into a uniform paste. The shellac is usually in an alcoholic solution. The following is a specific example of a mixture which we have found to be suitable for the purpose.

Shellac,'3 lbs. 2 ozs.

Denatured alcohol, 1 quart.

Whiting, 6 lbs. 10%; ozs.

The shellac is first dissolved in the alcohol, usually with the aid of stirring, after which the whiting is added slowly, with constant stirring, until a uniform, viscous, pasty mass is formed. The mixture is then placed in sealed containers to prevent evaporation of the solvent. This paste may be used for filling wood patterns in substantially the same manner as putty by being worked into place with the aid of a putty knife.

Patterns filled with our material have been subjected to various tests in order to determine the tenacity'with which the filler adheres to the wood, and, in all, cases, we have found that the pattern may be subjected to very i severe conditions without cracking or loss of any of the filler material. The tiller in a pattern repaired with. my new material has been hammered, and the pattern then immersed in wet sand for several weeks and then baked. Under all these cons ditions, the filler adhered tenaciously to the vood and was not injured in the least.

Although we have described the use of an alcoholic solution of shellac with whiting as a filling material, it is obvious that various equivalents of shellac, alcohol and whiting may be utilized. For instance, a phenolic condensation product or other natural or artificial resin may be substituted for shellac,

. acetone or other well-known solvent in place of alcohol and other inert filling materials.

such as lithopone or the like, may be used in 2. A Wood filler consisting of aviscous and six pounds, ten and one-half ounces solution of shellac and Whiting. I Whiting.

3. A Wood fillerconsisting-of a solution of In testimony whereof, We have hereunto 10 three pounds, two ounces shellac and six subscribed our names this 7th day of Decen1- 5 pounds, ten and one-half ounces Whiting. ber, 1920. I

4. A Wood filler consisting of three OTHO V. STEWART. pounds two ounces shellac, 1 quartalcohol, AUGUST R. HATZ'FELD. 

